Jordan’s King Abdullah II and the foreign powers most invested in his political survival will be hoping that his country isn’t about to demonstrate Trotsky’s maxim that all revolutions are impossible until they become inevitable. It was hardly Tahrir Square, but the 2,000 or so demonstrators that gathered in the heart of Amman and hundreds more in 12 other cities on Tuesday to protest a series of fuel-price hikes ordered by the government was a sign that the kingdom’s immunity to the Arab Spring may be ending. Indeed, many of the demonstrators took the unprecedented step of chanting not only for the restoration of fuel subsidies, but for revolution and the downfall of the regime. Publicly criticizing the King is a crime punishable by up to three years imprisonment in Jordan, yet protesters chanted “Freedom is from God, in spite of you, Abdullah.” Activists have called a general strike for Wednesday, and regardless of its level of support, the factors driving the growing challenge to the Hashemite throne are products of a deep structural malaise. It may long have been a bedrock of pro-Western, Israel-friendly stability in the Arab world, but the Kingdom of Jordan’s recipe for domestic political tranquility appears to be unraveling.

Amman saw even larger protests last month, as the Muslim Brotherhood‘s Islamic Action Front (IAF) and leftist parties rallied 15,000 demonstrators against the restrictive electoral law governing the Jan. 23 parliamentary elections and the limited powers of the parliament it will choose. While that turnout was smaller than the 50,000 promised, it was nonetheless a significant number in a country of just 6 million that is kept in line by an iron-fisted mukhabarat (internal security service). And protests have continued, fueled by a toxic cocktail of some of the highest unemployment and underemployment rates in the Arab world, declining real incomes and rising inequality, and widespread anger at rampant corruption and heavy-handed authoritarianism. That may sound like a classic prerevolutionary tinderbox, but the regime has long survived by its skillful manipulation through the patronage of deep social divisions, most notably between the traditionally loyalist Bedouin tribes known as East Bankers and the kingdom’s Palestinian majority. The usefulness of a staunchly pro-Western security state geographically lodged in the fulcrum between Israel, Syria and Iraq also gives the U.S. considerable incentive to help it survive the challenges of its restive citizenry.

What’s notable about the latest protests is that the rage appears to be equally, if not more, intense among the youth of those tribal structures that have long been the regime’s bedrock and offered preference in a number of forms of state employment, particularly in the security forces. The fact that Tuesday’s protests were sparked by the government’s announcement of a sudden hike in fuel prices suggests that the kingdom’s increasingly precarious economic situation has eroded its capacity to buy off key constituencies. By some estimates, various forms of subsidy account for as much as one-third of the government’s budget and more than 8% of GDP, and the authorities raised fuel prices in a desperate attempt to close a $5 billion budget deficit. Jordan remains heavily dependent on large infusions of cash from international lenders and friendly oil monarchies, and its coffers have been heavily stretched by rising costs of energy imports from Iraq after the natural gas pipeline from Egypt was taken off-line after repeated sabotage by militants. The presence of upwards of 100,000 refugees and counting from the civil war in neighboring Syria is adding to the burden and the resultant social tensions.

“The long-standing political exclusion of the Palestinian-dominated urban population, dwindling government funds to pay off the King’s East Bank tribal base and widespread corruption are provoking deep discontent,” says Julien Barnes-Dacey, a senior policy fellow at the European Council on Foreign Relations. “The King has tried to avert unrest through a combination of largely cosmetic reform measures and external financial support, but the credibility of the reform process is increasingly questioned, and Gulf states have delivered considerably less money than was promised. The increase in fuel prices is a stark wake-up call that Jordan can no longer pay its bills and that the result could well be popular unrest.”

Mindful of the danger that social protest could follow the Tunisia trajectory and explode into a revolutionary challenge, Abdullah two years ago sought to inoculate his regime from the wave of rebellion sweeping the Middle East by initiating a series of reforms ostensibly aimed at creating a more inclusive and representative system of government. But opposition groups accuse the palace of backsliding on reform, setting strict limits on the powers of the parliament to be elected on Jan. 23 and adopting an electoral law that dramatically overrepresented rural Bedouin constituencies, while dramatically underrepresenting the cities — where the predominantly Palestinian population would provide the base of the Muslim Brotherhood and leftist parties.

Abdullah has certainly made a habit of changing his mind, appointing and then firing four Prime Ministers since he embarked on the reform program. Observers in Amman believe the King’s confidence in surviving the Arab Spring grew as Saudi Arabia rallied for counterrevolution, and Western powers became increasingly concerned by Islamist gains in the emerging Arab democracies. As a result — and perhaps prodded by the mukhabarat and other key elements of the current regime with little enthusiasm for greater democracy, accountability and transparency — his enthusiasm for a genuinely open and competitive political system has declined. In short, Abdullah may believe Jordan is too important to its outside backers to be allowed to fail and therefore that he can set the terms and limits of any political change. Those limits have prompted the Brotherhood’s IAF and other political parties to boycott the January poll, which would negate the entire exercise by denying it the legitimacy that would be established by opposition participation. As things stand, the combination of the electoral law and the boycott make it likely that the new parliament will closely resemble the current one, leaving the political process unable to quiet or channel popular discontent.

“Without genuine reform aimed at securing a more inclusive political system — hitherto resisted by the King — it’s hard to see how he can deal with the deep economic problems without provoking wider unrest,” warns Barnes-Dacey. “These latest protests may fade away quietly, but the reality is that the Kingdom faces very serious challenges, which it is struggling to address, making the King increasingly the target of protest anger.” Indeed, Abdullah knows his presence on the throne is deemed indispensable to Western powers, Gulf monarchies and Israel. His problem lies in convincing his own people of the same.

Tony Karon is a senior editor at TIME, where he has covered international conflicts in the Middle East, Asia, and the Balkans since 1997. A native of South Africa, he now resides with his family in Brooklyn, New York.